We request a Zeiss LSM 510-Meta confocal microscope for sensitive fluorescence imaging of a variety of cells and tissues. The microscope will serve 8 major users and at least 50 minor users from multiple departments throughout the Johns Hopkins University Medical School. The users require a microscope that provides maximum sensitivity and spatial resolution, minimum crosstalk and bleedthrough, high speed and throughput, flexibility of raster scanning and wavelength analysis for FRET and FRAP, and robust software for image processing and analysis. The features of the Zeiss 510 confocal include: multitracking technology for speed and precise pixel localization; a Meta multi-channel spectrometer and software for distinct separation of overlapping fluorescence emission signals, and Zeiss LSM 510 and Axiovision software for rapid signal processing and analysis. The Zeiss 510 microscope will be installed in a centralized microscope core facility in the basic sciences where it will be supervised and maintained. The application is supported by a broad base of interest, need, and financial support by the university and will serve a large NIH-funded scientific community.